The present invention relates to a device for supporting rolls rotatably in an arrangement such as a rolling mill in a steel plate rolling line.
For example, molten steel having completed its refining is cast into slabs by continuous casting before rolling-worked into strips (band steels) using a hot strip mill (hot rolling mill). The slabs are heated up to rolling temperatures in a heating furnace in advance of the rolling, and fed to a rough finishing strand and a finishing strand of the hot strip mill successively, thereby being hot rolled to a prescribed wall thickness. Then, the strips (band steels) out of the finishing strand of the hot strip mill are cut into regular sizes by a flying shear, or reeled into a coil shape by a coiler; and those reeled by the coiler are, for example, subjected to processing such as pickling before cold rolled by a cold strip mill (cold rolling mill).
Rolling mills in steel plate rolling equipment as described above include many types such as a two-stage rolling mill, a three-high rolling mill, a four-high rolling mill, a multi-high rolling mill, and a Steckel rolling mill. A four-high rolling mill, for example, has such a configuration that the rolling of materials are performed between a pair of work rolls of relatively small diameter, above and below which backup rolls of relatively large diameter are arranged to prevent the deflection resulting from the rolling load of the work rolls. The respective rolls are supported rotatably to housings by double row or multi-row roller bearings, and the housings are supported by roll stands. Owing to load conditions, ambient temperatures, and the presence of foreign matter such as cooling water, water vapor, and scale, roll supporting apparatuses of this type are under a severe condition in the lubrication inside the roller bearings, and the design for the extension of life is one of major problems.